(a) Field of the Invention
The present invention relates to a grooved traverse drum used in a drum winder for winding a yarn into a cone cheese, especially having a large cone angle.
(b) Description of the Prior Art
Heretofore, when a yarn, especially one which is subject to damage due to the transmission of heat, such as synthetic fiber yarn, is wound into a cone cheese on a taper tube contacted with and rotated by the peripheral surface of a grooved traverse drum (hereinafter referred to simply as a drum), damage, such as yarn breakage, often occurs at the small-diameter end of the cheese. More specifically, when the cone cheese is rotated by the drum surface, the position at which the cone cheese is rotated by the drum is a position displaced from the center of the cone cheese toward the large-diameter side thereof. As a result, it is only at said position that the cone cheese can be rotated at a peripheral speed substantially equal to that of the drum at said position. Thus, at the small-diameter end farthest from said position, the considerable difference in peripheral speed causes a large amount of slippage in the direction of rotation. Therefore, the actual state is that the heat of friction due to said slippage causes damage to the yarn including yarn breakage. This tendency becomes the stronger, the greater the cone angle of the cheese. The damage, such as yarn breakage, has interfered with the subsequent unwinding of the cone cheese.
To overcome these difficulties, various proposals have been made but no satisfactory results have been obtained.